This invention relates to a substrate treating apparatus for performing a series of treatments of substrates such as semiconductor wafers, glass substrates for liquid crystal displays, glass substrates for photomasks, and substrates for optical disks (hereinafter called simply “substrates”).
Conventionally, this type of substrate treating apparatus is used to form a resist film on substrates, and develop the substrates exposed in a separate exposing machine. The apparatus includes a treating section having arranged therein at least a coating block for forming film such as resist film, a developing block for developing the substrates, and. Each treating block includes a single main transport mechanism and various treating units. The treating units of the coating block include coating units for applying treating solutions to the substrates, and heat-treating units for heat-treating the substrates. The main transport mechanism of each block, while transporting substrates to the treating units in that block, transfers the substrates through receivers to and from the main transport mechanism of another adjacent treating block, to carry out a series of treatments of the substrates (as disclosed in Japanese Unexamined Patent Publication No. 2003-324139, for example).
The conventional apparatus with such a construction has the following drawbacks.
In the conventional apparatus, when the main transport mechanism of the coating block transfers a substrate to the other adjacent main transport mechanism, the substrate cannot be placed on a receiver if, for example, a different substrate is present on that receiver. In such a case, the main transport mechanism of the coating block stands by until the receiver becomes capable of receiving the substrate. While the main transport mechanism of the coating block is on standby, the main transport mechanism does not transport substrates between the treating units of the coating block. For example, even when a substrate has been treated in a coating unit, this substrate is not transported to another treating unit such as a heat-treating unit. Therefore, the coating block cannot carry out a series of treatments including coating treatment and heat treatment in a predetermined time. As a result, there is an inconvenience of lowering the quality of treatment of the substrates.